in Episode IV, Luke is trained to deflect with a lightsaber. I hope someone can answer my questions about this.

Where did Ben get the seeker droid? I don't think Han would have one of those, or admit to it. I think he got it from the temple, to train future jedi. without telling Yoda.

-What is the helmet that Ben puts on Luke usually used for? It obviously belongs to Han, but the only clue to what it's used for is when Luke says,

"but with the blast shield down, I can't see, how am I supposed to fight?"

blast shield for what? Why cover your face with a blast shield?